Electric generator unit



Oct.. 31, 1939. F, BRACKEN ET AL 2,177,687

ELECTRIC GENERATOR UNIT Original Filed Nov. 19, 1937 2 Sheets-Sheet l I'Il 1N VENTOR5 ATTORNEY.

l Get. 3 1, 1939, F. BRACKEN r A1.` 2,177,687

ELECTRIC GENERATOR UNIT.l

Original Filed NOV. 19, 1937 2 Sheets-Sheet 2 INVENTORS fPAN/f BRAC/fewBY Passt-L A7550 ATTORNEY.

Patented Oct. 31, 1939 UNITED STATI-:s

ELECTRIC GENERATOR UNIT lirankl Bracken and Russell Reed, Los Angeles,Calif., assignors to Warner Bros. Pictures, Inc., ANew York, N. Y., acorporation o! Delaware l Original application November 19, 1937, SerialNo.

Divided and this application Septembel' 10, 1938, Serial No. 229.346

9 Claims.

This invention relates to electricgenerator units and has the followingobjects: To reduce the noise of an internal combustion engine andgenerator driven thereby; to direct the noise of an engine drivengenerator assembly in a predetermined path, to increase the eillciencyof a cooling system for an engine and generator driven thereby, toutilize a cooling system of an internal combustion engine to cool anelectric generator driven by the engine; to increase the flow of air inthe cooling system for an engine driven generator unit, and to produce acompact engine driven generator assembly.

The manner in which the above and other objects of the invention isaccomplished will be apparent from the following speciilcation read inconjunction with the accompanying drawings wherein:

Fig. 1 is a sectional, elevational view through an engine drivengenerator assembly embodying the present invention.

Fig. 2 is a sectional plan view of the generator assembly and is takenalong the lines 2-2 of Fig. 1.

Fig. 3 is an end view of the generator assembly .,gyith the rear panelremoved and is taken in the 'direction of the arrow 3 of Fig. l.

Fig. 4 is a perspective View of the rear of the generator assembly.

Fig. 5 is a sectional, elevational view of the fan drive and is takenalong the line 5-5 of Fig. 2.

Fig. 6 is a sectional view, partly broken away, of one of the waterjacketed exhaust manifolds.

Fig. '7 is a sectional View, partly broken away, through the generatorassembly showing a modied form of fan drive.

Referring particularly to Figs. l, 2 and 3, the engine-generatorassembly comprises an electric generator generally indicated at I0 and agasoline engine of the il-type generally indicated at II.

The generator I9 is of the usual construction cornprisingeJ circularcasing I2 enclosing both the eld coils (not shown) and the armature I3.

The armature shaft I3 of armature I3 is rotatably carried at one endthereof in an outboard bearing I4 supported from the casing I2 through aspider shaped bracket I5.

The gasoline engine II is also of the usual construction comprising acrankcase I 6 and a pair of cylinder blocks I1 and I8 secured thereto ina V-formation. The crank shaft I9 of the engine is suitably connected ina manner not 55 shown to the armature I3 for rotating the same.

A ange 20 at the rear of the engine is secured to the generator I0through bolts 2|, forming an integral engine-generator unit.

The rear of the engine-generator unit is supuv ported by means of Wheels23 an@ 24, Bespe- (cl. 29o-.1)

tive. shafts 23' and 24' of wheels 23 and 24 are carried by brackets and26, respectively, secured on either side of the generator casing I2 bybolts 21.

A sub chassis is provided to support the forward end of theengine-generator unit on a single steerable Wheel 28. This chassiscomprises a pair of longitudinally extending channel members 30 and 3|on either side of the crankcase I6 of engine II. Each of the channelmembers 36 ,and 3| are secured to the sides of the crankcase I6 by aseries 'of bolts32. A cross bar 33 is secured across the members 36 and3| by bolts 34 and has formed in the center thereof a verticallyextending bearing to rotatably receive an upwardly extending bearingstud projecting from a wheel saddle 36. Saddle 36 has secured to thelower ends thereof the shaft 31 of wheel 28. A draw bar 38 is secured tothe shaft 31 for the purpose of moving and steering the unit.

The forward ends of the channel members 30 and 3|, forming part of thesub-chassis, are secured, as by welding, to a cross piece 40 formingpart oi a panel frame generally indicated at 39. Longitudinallyextending frame beams 4| and 42, also forming part of the panel frame 39are secured at either end of the cross piece 40. The opposite ends ofthe members 4| and 42 are welded to a second cross piece 43. The rearsection of the panel frame 39 is supported from the generator I2 throughbrackets 44 and 45, (Fig. 3) which brackets secure the cross bar 43 tothe spider bracket I5 of the generator I2 by bolts 46. Vertical cornerposts comprising structural angles 41, 48, 49 and 50, also forming partof the panel frame 39 are suitably secured at their lower ends to thecorners of the rectangular frame comprising the members 40, 4|, 42 and43. Structural ties 5|, 52, 53 and 54 completing the panel frame 39 aresecured between the upper ends of the 'corner posts 41 to 5U, inclusive.

A series of sound insulating panels 55, 56, 51 and 58, enclosing thesides of the panel frame 39, form an enclosure open at its bottom andtop ends to form an air and sound conduit therethrough. Each of thesepanels comprises an outer sheet of metal 59 and an inner sheet of soundabsorbing and reproof material 59', such as asbestos, secured thereto toreduce the transmission of sound therethrough.

An air cooled heat radiating Water radiator 60 is suitably secured inthe upper end 'of the panel frame and substantially ills the same. Theradiator 60 slopes downward slightly, for example, at the front endthereof to permit a drainage of the water therein toward the front ofLthe unit. A protective wire screen of wide mesh 6| is supported abovethe surface of the radiator 60 to prevent damage to the radiator from.falling objects. 'I'he position of the radiator in a horizontalposition not only permits it to be cooled in part by the naturalconvection of the air but results in a more unitary and compactstructure for the same amount of radiator surface. Furthermore, theradiator is situated in a safe and unobstructing position permittingready access to all parts of the generator and motor.

The water cooling system for the engine I I comprises a water pump 62having an inlet 68 and an outlet 64, which pump is driven by a suitablemotor 65. Pump 62 may alsobe coupled to the cam shaft of engine Il. Theinlet 63 is connected to the outlet end of the radiator 60 through aninlet pipe 66. Flexible hose couplings 6l and 68 are provided toresiliently support the pipe 65 between the inlet 63 of pump 62 and theoutlet 88 of of the radiator 60 to prevent breakage thereof due tovibration or misalignment of the radiator relative to the engine I. Theoutlet 64 of the water pump 62 is connected through a flexible hosecoupling 69 to a T 10. One end of the T 'I0 is connected to the watercooling passages (not shown) of the cylinder block I8 through aconnection 90. The other end of the T 'I0 is con-.- nected through aconduit 1|, passing through the crankcase I6, to a connection 9| (Fig.3) communicating with the water cooling passages in the opposed cylinderblock II. After passing through the water cooling passages of the cylinder blocks |'I and I8, the water is passed through short conduits 'I2opening into water jackets 'I4 and l5, respectively. Return conduits I6and 'Il' Vare connected between the water jackets N and 18,respectively, and the rear end of the radiator 80 to return the heatedwater to the radiator for cooling.

The water jackets 'I4 and 'I5 enclose a portion of the exhaust manifolds'I8 and 19, respectively, which are connected through conduits 80 (Fig.6) to the interiors of the exhaust chambers of the respective cylinderblocks. The manifolds 'I8 and 19 pass above the radiator 60 and openinto separate sound absorbing "muillers 8| and 82, respectively.

The radiator 60 is cooled by a series of fans 83, 84 and 85. The fan 83is driven fom the cam shaft of the engine through a gear unit generallyindicated at 86 (Fig. 5). Unit 86 comprises a pair of beveled gears 8land 88, the gear 88 being secured to the end of the cam shaft 89 ofmotor II. 'I'he gear 81 is secured to the Y lower end of a shaft 90journaled within bearings 9| and 82 formed in upper and lower gearcasings 93 and 94, respectively. The upper gear casing 83 is supportedfrom the lower casing 94 by a tubular column 13. The pinion gear 95,secured to the upper end of the shaft 90, meshes with a gear 96, securedto the fan shaft 91. 'I'he shaft 91 is journaled within bearings formedin the upper gear casing 93 and has secured thereto a belt pulley 98adapted to drive a continuous belt 99. The fans 84 and 85 are secured tovertically extending shafts |00 and |0I, respectively, Journaled withincolumns |02. and |03, respectively. The column |03 is secured to theupper surface oi' the casing |2 of generator I0, while the column |02 issecured to a cross plate |04 (Fig.'2) suitably supported between the twocylinder blocks |'I and |8. Pulleys |05 and |06 are secured to the fanshafts |00 and |0|, respectively.

A modified formof fan .drive is shown in Fig. 7 wherein the fans etc.are driven from the generator shaft I3 instead of from the cam shaft 89of engine n. In tmsease the casings 83. $4,

and column 'I3 (Figs. 1 and 5) are retained merely to provide bearingsfor the 1an shaft 8l, the shaft and gears associated therewith beingremoved. A'pulley 4 (Fig. 7) is secured to the end of generator shaft I8to drive an endless belt H0. Belt ||6 travels over a pair o! co-sxialidler pulleys, one of which is shown at III, and around a pulley ||'I,secured to the fan shaft III oi' fan 85. A bracket ||8 rotatablysupports the cgi-axial pulleys from the top of generator casing I Inlieu of the above mentioned arrangements for driving the fans 88, 84 and86, an electric motor may be substituted, deriving its current from theoutput circuit of the generator I0.

It will be noted on reference to Fig. 2 that the shaft |00 of fan 84 isdisposed out of line with the centers of the other fans 83 and 85whereby a suiilcient amount of arcuate contact of the belt 99 on thepulley |05 is formed to insure a driving traction.

Muiliers 8| and 82 are supported above the radiator 60 on cross beams||0 and |I I. These beams are supported at their ends on thelongitudinally extending upper frame members 52 and 54, forming part ofthe panel frame 39. Semicircular straps H2 secure each of the mufliersIl and 82 to the cross beams |I0 and by bolts H3.

The transmission of sound from a medium of a. certain density to anothermedium of a dii'- ferent density will cause reilection and refraction ofthe sound to be set up at the juncture of the two mediums. Furthermore,the amount of reflection depends on the difference in density betweenthe mediums through which the sound is passed, it being greater forgreater diiferences in density. The muiliers 8| and 82 are arranged toutilize the above principle by spacing them apart, closely adjacent theedges of the side panels 65 and 56. Also the muiers are arrangedparallel with each other. Now, when the bank of heated air, carryingwith it the engine noises. is forced upwardly through the radiator 60 bythe fans 88, 84 and 85, it passes in contact with the muiilers 8| and82. Therefore, this bank of heated air will be further heated along thesides thereof due to its contact with the hot mumers which are in turnheated by the exhaust gases passing therethrough from the engine II.Thus it will be seen that the density of the heated air bank which isreduced due to the heat thereof will be further reduced along the sidesthereof because of additional heating imparted by the mufers 8| and 82.Consequently, a greater change' in density will be effected at theboundary of the heated air bank and the outer cool air resulting in agreater reflection and refraction of the sound waves within the airbank. This reflection and refraction of the sound waves will continueback and forth across and within the air bank as it is rising upwardlyfrom the generator unit thereby substantially confining the\ noisewithin the heated air bank and reducing the horizontal transmission ofsaid sound outside of the heated air bank.

Whether the above explanation is correct or not, the fact is that wehave successfully demonstrated that the method and means hereindisclosed provide a much quieter generator unit then heretofore.

I0 However, there is support for our view that a.

material part of the reduction of the various noises of the engine andgenerator is caused by the absorption of sound by the heated air throughwhich the various noises pass.

As will be noted in Figs. 1 and 3 the outlet conduits H4 and ll5 of themuillers 8l and 82, respectively, are returned to a central positionreiative to the radiator and terminate in an upwardly extending positionto direct the exhaust gases upwardly in the rising air currents. Theexhaust of the exhaust gases in an upward direction as well as the heatproduced by the mufilers 8i and 82 increases the natural convection ofair through the enclosure formed by the various panels 55 to 58,inclusive, thereby reducing the transmission of exhaust and engine noisein a horizontal direction.

Due to the position of the muiilers within the vertically rising currentof air caused by the fans 83, 84 and 85, as well as due to the naturalconvection thereof, these muiilers will be cooled, thus reducing theexpansion of exhaust gases therein and consequently reducing the noisecaused by these gases.

'I'he cooling of the exhaust manifolds by means of the water jackets 14and 'l5 insures a minimum of heat being generated Within the enclosureformed by the panels 55 to 58, inclusive, while reducing the expansionof the gases within these manifolds with a consequent reduction in soundin the exhaust.

The particular arrangement of the radiator 80 above the motor I l andgenerator I2 and the provision for directing the air upwardly in avertical direction permits both the engine and particularly thegenerator to be cooled by the air passing upwardly through the enclosurebefore it is warmed by -passage through the radiator. This particulararrangement also insures that all parts of the engine-generator unit aswell as the radiator 60 are equally exposed to the draft of cooling air.Furthermore, the use of a plurality of fans insures a uniform cooling ofthe entire surface of the radiator 60 while permitting a relatively slowperipheral speed of each fan to obviate the noisy whirl caused by thefan blades at high speed.

The invention is particularly applicable to portable engine drivengenerator units for use in supplying current to lamps, motors, etc. usedin photographing motion pictures while recording the sound incidentthereto. However. it is to be understood that the invention has numerousother fields of application. Further, while we have illustrated anddescribed our invention in its preferred embodiment, it is to beunderstood that various modications may be made and no limitations uponthe invention are intended other than are imposed by the scope of theappended claims.

This application is a division of application S.

N. 175,442 filed November 19th, 1937, for Engine driven generator systemand method of operating same.

We claim:

1. A motor generator set comprising a motor, a generator driven by saidmotor. a vertically extending enclosure surrounding said motor and saidgenerator, /said enclosure being open at the top and the bottom Vthereofand being adapted to transmit air throughout substantially the entirecross sectional area thereof around said ensine and said generator, acooling system for said engine, a radiator for said cooling system, saidradiator extending'across the top of said enclosure. and means forpassing air upwardly throuh said enclosure.

2. A motor generator set according to claim 1 comprising a muiiier forsaid motor extending above said radiator in the path of air passingthrough said enclosure.

3. A motor generator set comprising a motor, a 5 generator driven bysaid motor, a cooling system for said motor, a horizontally disposedradiator `for said motor extending above said motor and said generator,and a plurality of fans intermediate said radiator and said motorgenerator for 10 passing air upwardly around said motor and saidgenerator and through said radiator, one of said fans being adapted topass air around said generator and through said radiator and another ofsaid fans being adapted to pass air around said motor and through saidradiator.

4. A motor generator set comprising a motor, a generator driven by saidmotor, a cooling system for said motor, a radiator for said coolingsystem, means for passing air around said generator and 20 through saidradiator. and means other than said last mentioned means for passing airaround said motor and through said radiator.

5. A motor generator set comprising a m'otor, a generator driven by saidmotor and having an axis thereof aligned with the axis of said motor, aplurality of fans aligned in a row parallel to the axes of said motorand said generator, said fans being arranged to pass air transverselyaround said motor and said generator and means for driving said fans.

6. A motor generator set according to claim 5 comprising a coolingsystem for said motor, a radiator for said cooling system and meanssupporting said radiator in the path of said air on.v the side of saidfansopposlte said motor and said generator.

7. A motor generator set comprising an internal combustion motor, anelectric generator coupled thereto, an enclosure surrounding saidmotorand said generator and having an air inlet at the bottom thereof and anair outlet at the top thereof, a fan above said motor, a fan above saidgenerator, means for driving said fans, and a radiator for said motor insaid outlet common to 45 said fans.

8. A motor generator set comprising an engine.

a generator driven by said engine, a vertically extending enclosuresurrounding said engine and said generator, said enclosure being open atthe 50 top and bottom thereof, a cooling system for said engine, aradiator for said cooling system, said radiator extending across the topof said enclosure and means for passing ain upwardly through saidenclosure in substantially mutually 55 exclusive columns. one of saidcolumns passing around said generator and another of said columnspassing-around said engine.

9. A motor generator set comprising an internal combustion engine, agenerator coupled 00 thereto. an enclosure surrounding said motor andsaid generator-and having an air inlet at the bottom thereof and an airoutlet at thev top thereof, a muiller, means for conveying exhaust gasesfrom said engine to said muiller, and means for supporting said mul'lierabove said engine and said generator in the path of air passing throughsaid enclosure whereby to cause convection of air through saidenclosure.

, FRANK BRACKEN.

RUSSELL

